Not only do disasters affect individuals, but they also affect society as a whole. While it is understandable how disaster survivors and their family are the inevitable members of the affected population, other stakeholders like disaster workers (e.g. police, firefighters, healthcare workers and reporters) and the general public can also experience a certain level of impact. Disaster victims can be classified into ：
Disasters influence people to different extents. In "High risk population and other risk factors", you can find out more about those who might need more support to get through a disaster.
Primary & secondary victims
Who are primary & secondary victims? 
- Primary victims are those directly exposed to the traumatic event that may suffer from physical injuries, tangible losses and even the loss of loved ones.
- Secondary victims are the family and friends of primary victims. Witnessing the people they care about suffer, secondary victims also experience indirect impacts. How much they are affected depends on how close they are to the primary victims.
What challenges would they encounter? 
Environmental damages may lead to physical injury, loss of personal property and disruption of daily functioning. Loss of intimate families and friends may result in grief and sorrow.
Loss of intimate families and friends may result in grief and sorrow.
Intense emotional responses such as fear, anger, helplessness, worry and flashback of the traumatic experiences might arise. These emotional responses could be easily triggered by reminders or recollections of the incidents.
Shaken personal values of life could result from the unpredictable and sudden destruction to life and property. This may challenge people's beliefs about the world and themselves, leading to distress.
Who are tertiary victims?  
Tertiary victims are people who perform their unique duties during disasters, and may experience extreme occupational stress and fatigue, such as:
- Emergency workers, e.g. ambulance personnel, firefighters and police
- Healthcare workers, e.g. medical, nursing, mental health professionals and supporting staff
- Volunteers and humanitarian aid workers
- Spiritual care workers
What challenges would they encounter? 
Witnessing different kinds of tragedies and people in pain at the disaster site, no matter how strong one is, it is inevitable to be sentimental.
Some onsite challenges may include:
- Encounter of an overwhelming number of dead bodies and casualties
- Exposure to enormous suffering of injured survivors and their families
- Over-identification with survivors and families
- Uncertainty about reoccurrence of disaster
- Various safety risks during the performance of duties
- Loss of loved ones, colleagues and property in the disaster
- Sense of helplessness
The demands and work environment of deployment for disaster response can be radically different from routine duties. Disaster workers may feel the pressure to respond fast to the ever-changing disaster situation and make prompt and important decisions.
Further challenges may include:
- Change of work duties and arrangement under short notice, under which one may need to take up unfamiliar tasks
- Inadequate support on-site, e.g. insufficient provision of supplies and equipment
- Exceedingly demanding workload due to an upsurge of service needs or heightened public attention to their performance
- Lack of training to perform the required duties during disasters
- Ambiguous instructions, role delineation and expectations from the management
- Ineffective communication with survivors and families, among and across teams, departments or agencies
- Compromised physical and psychological well-being due to extended working hours
Infectious disease outbreak can impose high service demand which affects healthcare workers particularly.
Some distinct challenges may be:
- Risk of contagion
- Risk of spreading the disease further, e.g. families, friends and colleagues
- Uncertainty about the diseases and development of the outbreak
- Increased stigmatization and discrimination due to the constant contact with infected patients
- Increased workload due to a surge in service demand
- Physical discomfort due to the need to wear hot and uncomfortable personal protective equipment (PPE)
Why would the public fall victim to disasters?
It is because they may....
Feel disturbed under the exposure to vivid media reports about the disaster.
Identify with disaster survivors, i.e. developing sympathy and empathy with the injured and deceased and assimilate into their roles .
What would happen to them?
Feel sorry and sad for what happened 
Look for frequent updates on the events and become distressed by the exposure to emotionally disturbing descriptions and images in repeated media coverage
Worry that the misfortune could fall upon them and feel anxious and fearful 
Experience "compassion fatigue" , i.e. feeling emotionally numb about others' suffering  due to the feeling of helplessness 
High risk population and other risk factors
Disasters pose widespread influence on society. Some of you have higher resilience, while others may need more support. We can pay attention to the needs of  ：
Children and adolescents, especially if they i) have lost parental care and attachment, and ii) are affected by parent(s) under stress.
Women, especially if they lack social support, e.g. single mothers or widows.
Elderly, especially if they i) have pre-existing chronic health problems, and ii) have lost primary caregivers during disaster.
Other risk factors may make individuals more vulnerable to mental health problems  ：
- Socio-economic disadvantages
- Major life stressors (e.g. divorce, job and financial losses)
- Being ethnic minority
- Pre-existing physical disabilities
- Prior unresolved bereavement
- Pre-existing psychological problems
- Proximity to disaster
- Recurrence of disaster
- Experience of life-threatening danger or extreme violence
- Severe injury
- Experience of toxic contamination, in case of disasters involving toxins
- Witnesses of mass destruction and death
- Familiarity with disaster victims
- Sensing (e.g. seeing, hearing, smelling and feeling) the traumatic stimuli
- Disproportionate distress
- Persistent and excessive worry about safety of family members or significant others
- Lacking confidence in one's ability to cope
- Destruction of home, lives and the community
- Loss of important property
- Loss and injury of loved ones
- Multiple losses of the above
- Few, weak or deteriorating social resources
- Coping by avoidance, self-blame or substance abuse
- Poor emotional/ social support
- Insufficient problem solving skills
As family and friends of those in need of support, if you are wondering what you can do to make them feel better, take a look at Response: How to Offer Support for some suggestions.
-  Towards the classification of disasters and victims (Taylor, 1999).
-  Disaster triage and management manual (Hospital Authority, 2014).
-  Mental health services for victims of disasters (Cohen, 2002).
-  Adapted from Press Release, Division of Clinical Psychology, the Hong Kong Psychological Society.
-  Compassion Fatigue and Psychological Distress Among Social Workers: A Validation Study (Adams, Boscarino, & Figley, 2006).
-  Compassion Fatigue, Psychology Today.
-  Mental health reactions after disaster (National Center for PTSD, 2010).